This invention generally relates to solar energy collectors in which fluid flowing through a continuous tube is heated by contact with a means for absorbing solar energy as a result of sun's rays falling on the absorber means and passing through a light transmitting plate.
There have been numerous types of solar energy collectors embodying this general concept. Such prior proposed collector constructions have had advantageous and disadvantageous features. In general the problems sought to be solved by such prior solar collector have included the provision of a sufficiently rigid structure adapted to be readily assembled and fabricated while remaining inexpensive, the preservation as long as possible of the light transmitting function of the collector so that the transmission of solar energy to a solar absorber means is as effective as possible, compensation in the structure for expansion and contraction of different materials and under a wide temperature range such as occurs between night and day and wherein during the day certain portions of the collector may reach temperatures of 350 degrees F. and more, the maintenance of a clear nonhumid atmosphere within a substantially sealed solar collector receptacle, a method of readily assembling a solar collector structure, and the provision of a most effective, efficient thermal conductivity between solar energy absorber plates and fluid carried in a continuous tube.
Some previous types of solar collectors are shown generally in U.S. Pat. Nos. 938,012, 1,125,113, 3,039,453 and 3,464,402.
Prior proposed solar collectors utilizing a thermal conductive material between a fluid carrying tube and solar energy absorber plates are disclosed in U.S. Pat. Nos. 3,952,725 and 4,027,652. Prior solar collectors have also employed desiccant material within a collector construction as disclosed in U.S. Pat. Nos. 3,990,429, 3,995,614 and 3,999,536.